dermoid cyst

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun pathology A type of teratoma or tumour, usually benign. It is in the form of a cyst or sac, and contains skin and sometimes hair, nails, teeth or other tissue.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a cystic tumor (usually benign) with a wall lined with epithelium and a cavity containing other material